Discovering Blender Sculpt: The First Installment.

I have always been sceptical of the blender sculpt system, I think this feeling originated from when it first came out. It was buggy as hell and I remember trying it out, after adding a few multi-resolution levels(layers) blender crashed on me. So it did not leave a great first impression and besides at the time there was no real way to implement it into the whole 3D pipeline(there was no render backing) in all honesty I found it pretty useless. But that was then and this is now, and blender sculpt has changed.

ZBrush, Mudbox and Blender Sculpt Mode

There was and still is this notion that you get from some blender users who try and pass blenders sculpt mode off as an equivalent to ZBrush… hmm well its similar up to a certain point and then its not! Firstly the technology is completely different, ZBrush use’s a mixure of multi-resolution mesh’s with pixol’s for its high detailed work. A pixol in simple terms is a pixel with a Z value(depth) or a 3D pixel. ZBrush in essence is a 3D paint program where you paint the detail on top of a mesh. I’ve tried the program myself and found it to be very restrictive and eventually lost interest in it. The main rival to ZBrush at this time is Mudbox which approaches the idea of high resolution modeling in the same way as Blender does with just multi resolution meshes. Mudbox  way of thinking is to use pure 3D polygon geometry, what you see is what you get and the user models the object the same way as if they where to mould a piece of clay. Zbrush is the painter and Mudbox is the sculptor.

Zbrush has one main advantage over its rival and that’s in terms of memory and system requirements. Mudbox uses a hell of a lot of polygons so it generally needs a good Graphics Cards but also plenty of memory and a decent processor to back it up. The same thinking should be applied to Blender Sculpt. I myself found that after using Blender Sculpt that my system will need an upgrade from its current 2GB of RAM to prehaps something like 4GB/6GB and maybe a new graphics card(well when I can afford one). I have just changed my operating system from a 32-bit to a 64-bit architecture before my new memory arrives. A 32-bit operating systems generally has a bottleneck when it comes to the amount of memory it can use, around the 4-3GB mark. An example of this could be that someone would have 4GB memory installed on there 32-bit system, Windows or Linux might show there is 4GB installed on your motherboard but that doesn’t mean that its using the full 4GB it might only be using 3.25GB.
So why does this matter?
The image below has a polygon/face count of about 720000 at multires Level 5 and the memory consumption is 240MB of course I can still go up to level six but this level is ideal without any lag in the 3D view. At level six I can still work with a slight lag after applying a few tricks. The face count is now around 3 Million and blender is using 1.5GB of memory but that’s where it stops, my system cant take level 7 without a good chance of blender crashing.

Warning contains nudity

Warning contains nudity

Trying to develop a general understanding of Blender sculpt and how to implement it.

Although I have used blender for a long time, I’ve just starting to get my head around sculpt mode…
Firstly let me say that Blender Sculpt it is a beautiful tool but pretty useless on its own, for example imagine I create one character which consists of 11 million polygons. Wow that’s great but do you think I could add another character to my scene with the same polygon count and render them out in under 5 minutes, of course not… I have more chance of seeing an alien pig fly! So using a number of multi-res objects in the same scene is out of the question. There is a way to overcome this problem and that is through the use of  render/texture baking(obviously Mudbox and Zbrush both bake too) . Render baking was introduced with Blender 2.46 and it allows users to bake detail from a mesh to a normal map from then on Blender Sculpt changed from a fun to a very powerful tool. This is how blender sculpt should be thought as, a tool not only for modeling but one to aid in the production of normal and displacement maps.

There is another down side to having a high level multi-res mesh and that’s with posing the character during sculpt mode. After sculpting the female form I discovered a few truths. One is that I was undoubtedly creating more work for myself after posing the character rather than just leaving it and then mirror sculpting it with the use of x co-ordinates. Another problem is that after posing certain parts, a hand for example would overlap another making it increasingly difficult to sculpt and add detail. What this all boils down too is that in future I will never pose my high multi-res models again(well maybe for anatomy study… an arm or a leg), its not worth the pain.

Something I noticed that cannot be done in blender sculpt… although I have a general idea why it can’t be done but the fact still remains that is frustrating. When I am in sculpt mode and then change to edit mode, blender does not allow me to add or delete the mesh topology. Yes I can move vertices’s, faces and edges but I can’t create them. This means that you have to be hundred and one percent happy with the base mesh before you apply multi-res.

4 Tips to speed up sculpt mode.

  • If you have a graphics card change the setting from quality to performance, we aren’t gaming here so there’s no need for quality graphics what’s needed is speed.
  • Change blender undo settings from 32 to a lower number, I have mine on 6.
  • Use the “partial redraw” when in sculpt mode look  in 3D view window, click the “Sculpt” button you’ll see it there.
  • There’s a masking option in sculpt mode and using it will speed up the 3D view, hold Ctrl+shift and select an area of the mesh with the left mouse button. You’ll notice that the area you selected is now the only thing visible. Alt+h to return back to normal.

In the next installment I will be exploring the sculpt mode.

Discovering Blender Sculpt: The Second Installment->


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